Updated results of a phase 2 study: Timdarpacept (IMM01) combined with azacitidine (AZA) as the first-line treatment in adults with chronic myelomonocytic leukemia (CMML).

• DOI: 10.1200/jco.2025.43.16_suppl.6577
• Publication Date: 2025-05-28T16:43:03Z
• Authors: Hongyan Tong; Sujun Gao; Wei Yang; Junmin Li; Qingsong Yin; Xingli Zhao; Xiaojing Yan; Sanfang Tu; Fei Li; Haiping Yang; Ronghua Hu; Shaoyuan Wang; Liya Ma; Zheng Dong; Qiying Lu; Wenzhi Tian; Zhi-Jian Xiao; Jianxiang Wang
• Keywords: Azacitidine; Chronic myelomonocytic leukemia; First line treatment

6577 Background: Timdarpacept is a recombinant signal regulatory protein α (SIRPα) IgG1 fusion that exerts anti-tumor activity via blocking “Don’t eat me” and activating the “Eat to induce strong antibody-dependent cellular phagocytosis (ADCP). Methods: The study (NCT05140811) assessed safety efficacy of combined with AZA as first-line treatment for newly diagnosed CMML patients. was administered intravenously at dosage 2.0mg/kg/week, while subcutaneous given 75 mg/m 2 on D1-7 per 28-day cycle. Results: At cut-off date Dec 31, 2024, 24 patients, median age 62, males 62.5%, 75.0% ECOG≥1, were enrolled. 33.3% 66.7% patients high risk (HR), respectively. Majority had poor baseline hematologic conditions hemoglobin (Hb) level 69.5 (32-132) g/L platelet (PLT) count 73.5 (5-667)×10 9 /L. duration follow-up 21.0 months (95%CI, 19.3-23.3). Among 22 evaluable overall response rate (ORR) 72.7%, including 27.3% complete (CR), 13.6% marrow CR (mCR) improvement (HI), 4.5% HI mCR alone. time (TTR) 1.8 (DoR) 16.9 (95%Cl, 5.1-not reached [NR]). (TTCR) 3.7 (DoCR) 13.6 5.7-NR). progression-free survival (PFS) 17.8 5.3-NR), an estimated 12-month PFS 59.0% 33.4-77.6). Median OS has not been yet. most common ≥Grade 3 TRAEs (≥10%) included lymphopenia (66.7%), leukopenia (62.5%), neutropenia (58.3%), thrombocytopenia (50.0%), anemia (29.2%) pneumonia (16.7%). Without using low dose priming regimen, Grade ≥3 hemolysis occurred in 1 patient (4.2%). Conclusions: Timdarpacept, without low-dose priming, AZA, well tolerated 1L CMML. combination, when compared historical data monotherapy, showed promising results treatment-naive CMML-1 -2. Clinical trial information: NCT05140811 .